Creating ad-hoc connections

Creating ad-hoc connections#

The quickconnect extension provides a connection bar on the Guacamole Client home page that allows users to type in the URI of a server to which they want to connect and the client will parse the URI and immediately establish the connection. The purpose of the extension is to allow situations where administrators want to allow users the flexibility of establishing their own connections without having to grant them access to edit connections or even to have to create the connections at all, aside from typing the URI.

Important

There are several implications of using this extension that should be well-understood by administrators prior to implementing it:

  • Connections established with this extension are created in-memory and only persist until the Guacamole session ends.

  • Connections created with this extension are not accessible to other users, and cannot be shared with other users.

  • This extension provides no functionality for authenticating users - it does not allow anonymous logins, and requires that users are successfully authenticated by another authentication module before it can be used.

  • The extension provides users the ability not only to establish connections, but also to set any of the parameters for a connection. There are security implications for this - for example, RDP file sharing can be used to pass through any directory available on the server running guacd to the remote desktop. This should be taken into consideration when enabling this extension and making sure that guacd is configured in a way that does not compromise sensitive system files by allowing access to them.

Warning

You will need to restart the Guacamole web application in order to complete configuration. Doing this will disconnect all active users, so please:

  • Do this only at a time that you can tolerate service unavailability, such as a scheduled maintenance window.

  • Keep in mind that configuration errors may prevent Guacamole from starting back up.

Installing/Enabling the quickconnect extension#

Guacamole is configured differently depending on whether Guacamole was installed natively or using the provided Docker images. The documentation here covers both methods.

Native installations of Guacamole under Apache Tomcat or similar are configured by modifying the contents of GUACAMOLE_HOME (Guacamole’s configuration directory), which is located at /etc/guacamole by default and may need to be created first:

  1. Download guacamole-auth-quickconnect-1.6.0.tar.gz from the release page for Apache Guacamole 1.6.0 and extract it.

  2. Create the GUACAMOLE_HOME/extensions directory, if it does not already exist.

  3. Copy the guacamole-auth-quickconnect-1.6.0.jar file from the contents of the archive to GUACAMOLE_HOME/extensions/.

  4. Proceed with the configuring Guacamole for the newly installed extension as described below. The extension will be loaded after Guacamole has been restarted.

Note

Download and documentation links for all officially supported extensions for a particular version of Guacamole are always provided in the release notes for that version. The copy of the documentation you are reading now is from Apache Guacamole 1.6.0.

If you are using a different version of Guacamole, please locate that version within the release archives and consult the documentation for that release instead.

Docker installations of Guacamole include a bundled copy of Apache Tomcat and are configured using environment variables. The startup process of the Docker image automatically populates GUACAMOLE_HOME (Guacamole’s configuration directory) based on the values of these variables.

If deploying Guacamole using Docker Compose:

You will need to add at least one relevant environment variable to the environment section of your guacamole/guacamole container, such as the QUICKCONNECT_ENABLED environment variable:

QUICKCONNECT_ENABLED: "true"
If instead deploying Guacamole by running docker run manually:

The same environment variable(s) will need to be provided using the -e option. For example:

$ docker run --name some-guacamole \
    -e QUICKCONNECT_ENABLED="true" \
    -d -p 8080:8080 guacamole/guacamole

If QUICKCONNECT_ENABLED is set to false, the extension will NOT be installed, even if other related environment variables have been set. This can be used to temporarily disable usage of an extension without needing to remove all other related configuration.

You don’t strictly need to set QUICKCONNECT_ENABLED if other related environment variables are provided, but the extension will be installed only if at least one related environment variable is set.

Configuration (optional)#

This extension has no required properties. So long as you are satisfied with the default behavior/values noted below, this extension requires no configuration beyond installation.

quickconnect-allowed-parameters

An optional list of parameters that are allowed to be used by connections that are created and accessed via the quickconnect extension. If provided, only parameters in this list will be allowed.

quickconnect-denied-parameters

An optional list of parameters that are explicitly denied from being used by connections created and accessed via the quickconnect extension. If provided, any parameters in this list will be removed from the connection configuration when it is created, even if those parameters are otherwise explicitly listed as allowed.

This extension has no required environment variables. So long as you are satisfied with the default behavior/values noted below, this extension requires no configuration beyond installation.

QUICKCONNECT_ALLOWED_PARAMETERS

An optional list of parameters that are allowed to be used by connections that are created and accessed via the quickconnect extension. If provided, only parameters in this list will be allowed.

QUICKCONNECT_DENIED_PARAMETERS

An optional list of parameters that are explicitly denied from being used by connections created and accessed via the quickconnect extension. If provided, any parameters in this list will be removed from the connection configuration when it is created, even if those parameters are otherwise explicitly listed as allowed.

Completing installation#

Guacamole will only reread its configuration and load newly-installed extensions during startup, so Tomcat will need to be restarted before these changes can take effect. Restart Tomcat and give the new functionality a try.

You do not need to restart guacd.

Hint

If Guacamole does not come back online after restarting Tomcat, check the logs. Configuration problems may prevent Guacamole from starting up, and any such errors will be recorded in Tomcat’s logs.

The environment variables that configure the behavior of Docker can only be set at the time the Docker container is created. To apply these configuration changes, you will need to recreate the container.

If your Guacamole container was deployed using Docker Compose:

Simply making the desired changes to your docker-compose.yml and running docker compose up is sufficient. Docker Compose will automatically recognize that the environment variables of the container have changed and recreate it.

If your Guacamole container was deployed manually (using docker run):

You wll need to manually use docker rm to remove the old container and then manually recreate it with docker run and the new environment variables.

Hint

If Guacamole does not come back online after recreating the container, check the Docker logs. Configuration problems may prevent Guacamole from starting up, and any such errors will be recorded in the Docker logs for the Guacamole container.

Using the quickconnect extension#

The quickconnect extension provides a field on the home page that allows you to enter a Uniform Resource Identifier (URI) to create a connection. A URI is in the form:

protocol://username:password@host:port/?parameters

The protocol field can have any of the protocols supported by Guacamole, as documented in Configuring Guacamole. Many of the protocols define a default port value, with the exception of VNC. The parameters field can specify any of the protocol-specific parameters as documented on the configuration page.

To establish a connection, simply type in a valid URI and either press “Enter” or click the connect button. This extension will parse the URI and create a new connection, and immediately start that connection in the current browser.

Here are a few examples of URIs:

ssh://linux1.example.com/

Connect to the server linux1.example.com using the SSH protocol on the default SSH port (22). This will result in prompting for both username and password.

vnc://linux1.example.com:5900/

Connect to the server linux1.example.com using the VNC protocol and specifying the port as 5900.

rdp://localuser@windows1.example.com/?security=rdp&ignore-cert=true&disable-audio=true&enable-drive=true&drive-path=/mnt/usb

Connect to the server windows1.example.com using the RDP protocol and the user “localuser”. This URI also specifies several RDP-specific parameters on the connection, including forcing security mode to RDP (security=rdp), ignoring any certificate errors (ignore-cert=true), disabling audio pass-through (disable-audio=true), and enabling filesystem redirection (enable-drive=true) to the /mnt/usb folder on the system running guacd (drive-path=/mnt/usb).

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